Organic light emitting diode display device having built-in touch panel and method of manufacturing the same

ABSTRACT

An organic light emitting diode (OLED) display device having a built-in touch panel and a manufacturing method thereof in which an OLED array and a touch array are formed on a flexible substrate and thus the OLED display device has flexibility, and a flexible printed circuit board for driving the touch array is integrally formed with a printed circuit board for driving the OLED array and thus manufacturing costs are reduced are disclosed. The OLED display device includes an OLED array formed on a lower flexible substrate, a touch array formed on an upper flexible substrate, and an adhesive layer adhering the upper flexible substrate to the lower flexible substrate such that the touch array and the OLED array face each other.

This present patent document is a divisional of U.S. patent application Ser. No. 13/943,149, filed Jul. 16, 2013 which claims the benefit of priority of Korean Patent Application No. 10-2012-0147137, filed on Dec. 17, 2012, which is hereby incorporated by reference as if fully set forth herein.

FIELD OF THE DISCLOSURE

The present disclosure relates to an organic light emitting diode (OLED) display device having a built-in touch panel, and more particularly, to an OLED display device having a built-in touch panel in which an OLED array and a touch array are formed on respective flexible substrates and thus the OLED display device has a decreased thickness and improved flexibility and a manufacturing method thereof.

DISCUSSION OF THE RELATED ART

Image display devices, which display a variety of information on a screen, are a core technology of information and communication and are developed towards a trend of thinner, lighter, portable, and high performance. Thus, organic light emitting diode (OLED) display devices, which display an image by controlling emission amount of an organic emission layer (EML), have received attention as a flat panel display device that may address problems in terms of weight and volume which occur in cathode ray tubes (CRTs).

An OLED display device includes an OLED, which is self-emissive and emits light using a thin EML between electrodes, and thus may be realized as a thin film such as paper.

An OLED array includes a thin film transistor (TFT) formed in each subpixel region of a substrate and the OLED connected to the TFT and including a first electrode (i.e., anode), an EML, and a second electrode (i.e., cathode) which are sequentially formed. When a voltage is applied between the first and second electrodes, holes and electrons are recombined in the EML to form excitons and, when the excitons drop to a ground state, light is emitted.

In particular, the OLED array is formed on a flexible substrate and thus an OLED display device having flexibility may be manufactured. More particularly, an exfoliation layer is formed on a rigid substrate formed of, for example, glass, the flexible substrate is formed on the exfoliation layer, and the OLED array is formed on the flexible substrate. Subsequently, the exfoliation layer is separated from the flexible substrate.

Meanwhile, to manufacture a flexible OLED display device, an encapsulation substrate covering an OLED array is also formed of a plastic film. However, it is impossible to perform a manufacturing process such as chemical vapor deposition (CVD), sputtering, or the like on the film. Thus, only an add-on type in which a touch array is attached to a film may be applied to the flexible OLED display device.

SUMMARY

An OLED display device includes an OLED array formed on a lower flexible substrate, a touch array formed on an upper flexible substrate, and an adhesive layer adhering the upper flexible substrate to the lower flexible substrate such that the touch array and the OLED array face each other.

The touch array may include X and Y electrodes crossing each other, a pad part, and a routing line connecting the pad part to the X and Y electrodes, wherein the pad part is connected to the OLED array via an anisotropic conductive paste.

In another aspect of the present invention, a method of manufacturing an OLED display device having a built-in touch panel includes forming a lower flexible substrate on a lower rigid substrate with a lower exfoliation layer positioned therebetween and forming an OLED array on the lower flexible substrate, forming an upper flexible substrate on an upper rigid substrate with an upper exfoliation layer positioned therebetween and forming a touch array on the upper flexible substrate, adhering the upper rigid substrate to the lower rigid substrate using an adhesive layer such that the touch array and the OLED array face each other, separating the upper exfoliation layer from the upper flexible substrate, cutting the lower rigid substrate on a unit panel basis, and separating the lower exfoliation layer from the lower flexible layer.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:

FIG. 1 is a sectional view of an organic light emitting diode (OLED) display device having a built-in touch panel, according to an embodiment of the present invention;

FIG. 2A is a sectional view of an OLED array of the OLED display device of FIG. 1;

FIG. 2B is a sectional view of a touch array of the OLED display device of FIG. 1;

FIGS. 3A through 3H are sectional views sequentially illustrating a method of manufacturing the OLED display device having a built-in touch panel, according to a first embodiment of the present invention;

FIG. 4A is a photograph of an upper flexible substrate from which an upper exfoliation layer is separated using ultraviolet irradiation;

FIGS. 4B and 4C are photographs showing a case in which wiring defects of the touch array do not occur when the upper exfoliation layer is separated upon ultraviolet irradiation;

FIGS. 5A through 5F are sectional views sequentially illustrating a method of manufacturing the OLED display device having a built-in touch panel, according to a second embodiment of the present invention;

FIG. 6A is a photograph of an upper flexible substrate from which an upper exfoliation layer is separated by application of a certain voltage; and

FIGS. 6B and 6C are photographs showing a case in which wiring defects of a touch array do not occur when the upper exfoliation layer is separated by application of a voltage.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

Hereinafter, embodiments of an organic light emitting diode display device having a built-in touch panel will be described in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view of an organic light emitting diode (OLED) display device having a built-in touch panel, according to an embodiment of the present invention. FIG. 2A is a sectional view of an OLED array 140 of the OLED display device of FIG. 1. FIG. 2B is a sectional view of a touch array 160 of the OLED display device of FIG. 1.

As illustrated in FIG. 1, the OLED display device having a built-in touch panel includes the OLED array 140 formed on a lower flexible substrate 120 a and the touch array 160 formed on an upper flexible substrate 120 b. The lower and upper flexible substrates 120 a and 120 b are adhered to each other by an adhesive layer 170 such that the touch array 160 and the OLED array 140 face each other.

In particular, the lower flexible substrate 120 a is a plastic film formed of at least one organic material selected from among polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyethylene ether phthalate, polycarbonate, polyarylate, polyether imide, polyether sulfonate, polyimide, and polyacrylate.

A buffer layer 130 is formed between the lower flexible substrate 120 a and the OLED array 140. The buffer layer 130 improves adhesion between the OLED array 140 and the lower flexible substrate 120 a and prevents moisture or impurities from diffusing into the OLED array 140 from the lower flexible substrate 120 a. The buffer layer 130 may be a single layer structure of an inorganic insulator such as silicon oxide (SiO_(x)), silicon nitride (SiN_(x)), or the like or a double-layered structure of SiO_(x) and SiN_(x).

The OLED array 140 is formed on the lower flexible substrate 120 a with the buffer layer 130 positioned therebetween. As illustrated in FIG. 2A, the OLED array 140 includes a thin film transistor (TFT) including a gate electrode 140 a, a gate insulating layer 141, a semiconductor layer 142, a source electrode 143 a, and a drain electrode 143 b and an OLED including a first electrode 145, an organic emission layer (EML) 147, and a second electrode 148.

In particular, the gate electrode 140 a is formed on the buffer layer 130, and the gate insulating layer 141 is formed to cover the gate electrode 140 a. The semiconductor layer 142 is formed on the gate insulating layer 141 to overlap with the gate electrode 140 a. The source and drain electrodes 143 a and 143 b are formed on the semiconductor layer 142 to be spaced apart from each other.

An organic layer 144 formed of an acryl-based resin or the like is formed to cover the TFT. The organic layer 144 planarizes the lower flexible substrate 120 a on which the TFT is formed. Although not shown, an inorganic layer (not shown) formed of SiO_(x), SiN_(x), or the like is formed between the gate insulating layer 141 and the organic layer 144. The inorganic layer may improve the stability of an interface between the organic layer 144 and each of the gate insulating layer 141, the source electrode 143 a, and the drain electrode 143 b.

The second electrode 148 is formed on the organic layer 144 to cover the first electrode 145 connected to the drain electrode 143 b, a bank insulating layer 146 that partially exposes the first electrode 145, and the organic EML 147 formed on the exposed portion of the first electrode 145. The bank insulating layer 146 defines a light-emitting region of the OLED array 140 and prevents light leakage of a non-light-emitting region.

Referring back to FIG. 1, a passivation layer 150 is formed to cover the OLED array 140. The passivation layer 150 may have a single layer structure of an inorganic insulator, such as aluminum oxide (AlO_(x)), silicon oxynitride (SiON), silicon nitride (SiN_(x)), or silicon oxide (SiO_(x)) or an organic insulator such as benzocyclobutene or photoacryl. Alternatively, the passivation layer 150 may have a structure in which layers respectively formed of the inorganic insulator and the organic insulator are stacked one upon another.

Although not shown, a drive IC is formed at one side of the lower flexible substrate 120 a, and the drive IC is connected to a printed circuit board (PCB). The PCB includes a timing control unit (not shown) for supplying various control signals to drive the OLED array 140 and a power supply (not shown) to supply a driving voltage. A signal of the PCB is applied to the OLED array 120 a via the drive IC.

In particular, the PCB is integrally formed with a flexible PCB (FPCB) including a touch controller to drive the touch array 160. The FPCB is electrically connected to the touch array 160 via an anisotropic conductive paste (ACP), which will be described below.

The touch array 160 formed on the upper flexible substrate 120 b is adhered to the passivation layer 150 by an adhesive layer 170 so that the touch array 160 and the OLED array 140 face each other. In this regard, the upper flexible substrate 120 b is a plastic film formed of at least one organic material selected from PEN, PET, polyethylene ether phthalate, polycarbonate, polyarylate, polyether imide, polyether sulfonate, polyimide, and polyacrylate, like the lower flexible substrate 120 a.

In particular, as illustrated in FIG. 2B, the touch array 160 formed on the upper flexible substrate 120 b includes a plurality of X electrodes 161 a and a plurality of Y electrodes 161 b that cross each other with a first insulating layer 162 a positioned therebetween and take the form of a bar and a second insulating layer 162 b to cover the Y electrodes 161 b.

The X and Y electrodes 161 a and 161 b of the touch array 160 are connected to pad parts by routing lines. In this regard, the pad parts are voltage applying pads or voltage detection pads. The touch array 160 is of a mutual capacitive type in which a driving voltage is applied to the X electrodes 161 a and the Y electrodes 161 b sense voltage drop according to whether touch is performed or not.

In some embodiments, the touch array 160 may include bridge electrodes formed on the upper flexible substrate 120 b, a first insulating layer covering the bridge electrodes, X electrodes formed on the first insulating layer and electrically connected via the bridge electrodes, Y electrodes formed at the same layer level as the X electrodes, and a second insulating layer covering the X and Y electrodes.

Referring back to FIG. 1, the adhesive layer 170 is formed on the touch array 160. In addition, the adhesive layer 170 is attached to the passivation layer 150. In such a manner, the upper and lower flexible substrates 120 b and 120 a are adhered such that the touch array 160 and the OLED array 140 face each other.

Although not shown, the touch array 160 and the OLED array 140 are electrically connected to each other via an ACP. The ACP has a structure in which conductive balls coated with a metal such as gold (Au), silver (Ag), copper (Cu), molybdenum (Mo), or the like are dispersed in a sealant.

The ACP connects the pad parts of the touch array 160 to the FPCB. The pad parts are connected to X and Y electrodes 161 a and 161 b of the touch array 160 via routing lines.

In general, an FPCB to drive a touch array is separately formed from a PCB to drive an OLED array. However, in embodiments, the PCB to drive the OLED array 130 is integrally formed with the FPCB to drive the touch array 160, and the FPCB and the touch array 160 are connected to each other using an ACP.

Therefore, in the OLED display device having a built-in touch panel, manufacturing costs may be reduced by integrating the FPCB to drive the touch array 160 with the PCB to drive the OLED array 140.

In addition, a top cover 180 is attached to a rear surface of the upper flexible substrate 120 b on which the touch array 160 is formed. The top cover 180 is formed of a material having high transmittance and flexibility, such as polymethylmethacrylate (PMMA), polyurethane (PU), acryl, cyclo olefin polymer (COP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide, or the like.

In addition, although not shown, a bottom cover formed of a material, such as PMMA, PU, acryl, COP, PET, PEN, polyimide, or the like may be formed on a rear surface of the lower flexible substrate 120 a.

As described above, the OLED array 140 and the touch array 160 are respectively formed on the lower flexible substrate 120 a and the upper flexible substrate 120 b, and thus the OLED display device having a built-in touch panel has flexibility. In particular, a flexible substrate has a smaller thickness than a general rigid substrate and thus may enable reduction in display device thickness.

Moreover, the FPCB for driving the touch array 160 is formde on the PCB for driving the OLED array 140 and the FPCB is electrically connected to the touch array 160 via an ACP, and thus manufacturing costs may be reduced.

Hereinafter, a method of manufacturing the OLED display device having a built-in touch panel will be described in detail with reference to the accompanying drawings.

First Embodiment

FIGS. 3A through 3H are sectional views sequentially illustrating a method of manufacturing the OLED display device having a built-in touch panel, according to a first embodiment of the present invention. FIG. 4A is a photograph of the upper flexible substrate 120 b from which an upper exfoliation layer 110 b is separated upon ultraviolet irradiation. FIGS. 4B and 4C are photographs showing a case in which wiring defects of the touch array 160 do not occur when the upper exfoliation layer is separated using ultraviolet irradiation.

As illustrated in FIG. 3A, a lower exfoliation layer 110 a is formed on a lower rigid substrate 100 a such as a glass substrate, and the lower flexible substrate 120 a is formed on the lower exfoliation layer 110 a. The lower flexible substrate 120 a is a plastic film formed by coating the lower exfoliation layer 110 a with a polymer solution by slit coating, spin coating, or the like and curing the polymer solution coated thereon.

The plastic film is formed of at least one organic material selected from PEN, PET, polyethylene ether phthalate, polycarbonate, polyarylate, polyether imide, polyether sulfonate, polyimide, and polyacrylate.

As illustrated in FIG. 3B, the buffer layer 130 is formed on the lower flexible substrate 120 a. The buffer layer 130 improves adhesion between the lower flexible substrate 120 a and the OLED array 140, which will be described below and prevents moisture or impurities from diffusing into the OLED array 140 from the lower flexible substrate 120 a. The buffer layer 130 may have a single layer structure of an inorganic insulator such as SiO_(x), SiN_(x), or the like or a double-layered structure including two layers of SiO_(x) and SiN_(x).

Subsequently, as illustrated in FIG. 3C, the OLED array 140 is formed on the buffer layer 130, and the passivation layer 150 is formed on the OLED array 140. In particular, the OLED array 140 includes a TFT including a gate electrode, a gate insulating layer, a semiconductor layer, and source and drain electrodes and an OLED including a first electrode, an organic EML, and a second electrode.

First, the gate electrode is formed on the buffer layer 130, and the gate insulating layer is formed to cover the gate electrode. In addition, the semiconductor layer is formed on the gate insulating layer to overlap with the gate electrode, and the source and drain electrodes spaced apart from each other are formed on the semiconductor layer.

The organic layer 144 formed of an acryl-based resin or the like is formed to cover the TFT. The organic layer 144 planarizes the lower flexible substrate 120 a on which the TFT is formed. Although not shown, an inorganic layer formed of SiO_(x), SiN_(x), or the like is formed between the gate insulating layer and the organic layer 144 and thus may improve the stability of an interface between the organic layer 144 and each of the gate insulating layer, the source electrode, and the drain electrode.

The second electrode is formed on the organic layer 144 to cover the first electrode connected to the drain electrode, a bank insulating layer that partially exposes the first electrode, and the organic EML formed on the exposed portion of the first electrode. The bank insulating layer defines a light-emitting region of the OLED array 140 and prevents light leakage of a non-light-emitting region.

Next, the passivation layer 150 is formed on the OLED array 140. The passivation layer 150 may have a single layer structure of an inorganic insulator, such as AlO_(x), SiON, SiN_(x), or SiO_(x) or an organic insulator such as benzocyclobutene or photoacryl. Alternatively, the passivation layer 150 may have a structure in which layers respectively formed of the inorganic insulator and the organic insulator are stacked one upon another.

Subsequently, as illustrated in FIG. 3D, the touch array 160 is formed on the upper flexible substrate 120 b. In this regard, the upper flexible substrate 120 b is a plastic film formed by coating the upper exfoliation layer 110 b formed on an upper rigid substrate 100 b formed of glass with the above-described polymer by slit coating, spin coating, or the like and curing the polymer coated on the upper exfoliation layer 110 b.

Next, the touch array 160 is formed on the upper flexible substrate 120 b. The touch array 160 is formed such that a plurality of X electrodes and a plurality of Y electrodes that cross each other with a lower insulating layer positioned therebetween and take the form of a bar are formed on the upper flexible substrate 120 b and an upper insulating layer is formed to cover the Y electrodes. The X and Y electrodes are connected to pad parts by routing lines, and the pad parts are voltage applying pads or voltage detection pads.

The touch array 160 is of a mutual capacitive type in which a driving voltage is applied to the X electrodes and the Y electrodes sense voltage drop according to whether touch is performed or not.

In some embodiments, the touch array 160 may include bridge electrodes formed on the upper flexible substrate 120 b, an insulating layer covering the bridge electrodes, X electrodes formed on the insulating layer and electrically connected via the bridge electrodes, and Y electrodes formed at the same layer level as the X electrodes.

Next, as illustrated in FIG. 3E, the adhesive layer 170 is formed on the touch array 160, and the adhesive layer 170 is attached to the passivation layer 150. The lower and upper rigid substrates 100 a and 100 b are adhered by curing the adhesive layer 170 so that the touch array 160 and the OLED array 140 face each other.

Subsequently, as illustrated in FIG. 3F, an ultraviolet irradiator is positioned above the upper rigid substrate 100 b, and the upper rigid substrate 100 b is irradiated with ultraviolet light. The upper exfoliation layer 110 b loses adhesive strength upon ultraviolet irradiation and thus, as illustrated in FIG. 4A, the upper exfoliation layer 110 b is separated from a rear surface of the upper flexible substrate 120 b via ultraviolet irradiation. In this regard, as illustrated in FIGS. 4B and 4C, routing lines of the touch array 160 are not disconnected.

Although not shown, the lower rigid substrate 100 a is cut on a unit panel basis, and then the PCB for driving the OLED array 140 is integrally formed with the FPCB for driving the touch array 160. In addition, the FPCB is connected to the touch array 160 using an ACP. In this regard, the ACP has a structure in which conductive balls coated with a metal such as Au, Ag, Cu, Mo, or the like are dispersed in a sealant.

Subsequently, as illustrated in FIG. 3G, an ultraviolet irradiator is positioned below the lower rigid substrate 100 a, and then the lower rigid substrate 100 a is irradiated with ultraviolet light. As with the upper exfoliation layer 110 b, the lower exfoliation layer 110 a also loses adhesive strength upon ultraviolet irradiation and thus is separated from a rear surface of the lower flexible substrate 120 a by the irradiated ultraviolet light.

That is, in the OLED display device having a built-in touch panel described above, after removal of the upper rigid substrate 100 b, the OLED array 140 and the touch array 160 are cut on a unit panel basis and then the lower rigid substrate 100 a is removed. In another embodiment, however, after removal of the lower rigid substrate 100 a, the OLED array 140 and the touch array 160 may be cut on a unit panel basis and then the upper rigid substrate 100 b may be removed.

As described above, the lower and upper rigid substrates 100 a and 100 b are separately removed. This is because when the PCB for driving the OLED array 140, the ACP, and the like are attached to the lower and upper flexible substrates 120 a and 120 b in a case in which only the lower and upper flexible substrates 120 a and 120 b remain, the lower and upper flexible substrates 120 a and 120 b may bend, resulting in poor attachment.

Lastly, as illustrated in FIG. 3H, the top cover 180 is attached to the rear surface of the upper flexible substrate 120 b. The top cover 180 is formed of a material having high transmittance and flexibility, such as PMMA, PU, acryl, COP, PET, PEN, polyimide, or the like.

In addition, although not shown, a bottom cover may be formed on a rear surface of the lower flexible substrate 120 a. The bottom cover is formed of a material such as PMMA, PU, acryl, COP, PET, PEN, polyimide, or the like.

Second Embodiment

In a manufacturing method of the OLED display device having a built-in touch panel, according to a second embodiment of the present invention, an exfoliation layer formed between a rigid substrate and a flexible substrate is formed of a metal or a transparent conductive oxide and thus, when a high voltage is applied to the exfoliation layer, the exfoliation layer is separated from the flexible substrate.

FIGS. 5A through 5F are sectional views sequentially illustrating a method of manufacturing the OLED display device having a built-in touch panel, according to a second embodiment of the present invention. FIG. 6A is a photograph of an upper flexible substrate 200 b from which an upper exfoliation layer 210 b is separated by application of a certain voltage. FIGS. 6B and 6C are photographs showing a case in which wiring defects of the touch array 160 do not occur when the upper exfoliation layer 210 b is separated by application of a certain voltage.

As illustrated in FIG. 5A, a lower exfoliation layer 210 a is formed on a lower rigid substrate 200 a formed of, for example, glass, and a lower flexible substrate 220 a is formed on the lower exfoliation layer 210 a. In this regard, the lower exfoliation layer 210 a is formed of a metal such as molybdenum (Mo), aluminum (Al), or the like, or a transparent conductive oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), or the like.

The lower exfoliation layer 210 a is used to separate the lower rigid substrate 200 a from the lower flexible substrate 220 a. In this regard, when the thickness of the lower exfoliation layer 210 a is too small or too large, separation characteristics deteriorate when the lower exfoliation layer 210 a is separated from the lower flexible substrate 220 a. Thus, the thickness of the lower exfoliation layer 210 a may range from 1,000 Å to 3,000 Å.

The lower flexible substrate 220 a is formed on the lower exfoliation layer 210 a, and an OLED array 240 is formed on the lower flexible substrate 220 a, with a buffer layer 230 positioned therebetween.

The OLED array 240 includes a TFT and an OLED connected to the TFT. The TFT includes a gate electrode, a gate insulating layer, a semiconductor layer, and source and drain electrodes, and the OLED includes a first electrode, an organic EML, and a second electrode. A passivation layer 250 is formed on the OLED array 240.

Subsequently, as illustrated in FIG. 5B, a touch array 260 is formed on the upper flexible substrate 220 b. In this regard, as with the lower flexible substrate 220 a, an upper exfoliation layer 210 b is formed on an upper rigid substrate 200 b formed of, for example, glass. The upper exfoliation layer 210 b is also formed of a metal such as Mo, Al, or the like, or a transparent conductive oxide such as ITO, IZO, ITZO, or the like. The thickness of the upper exfoliation layer 210 b ranges from 1,000 Å to 3,000 Å.

Next, the upper exfoliation layer 210 b is coated with the above-described polymer using a method such as slit coating, spin coating, or the like and the polymer coated on the upper exfoliation layer 210 b is cured, to form the upper flexible substrate 220 b. Subsequently, the touch array 260 is formed on the upper flexible substrate 220 b. The touch array 260 includes a plurality of X electrodes and a plurality of Y electrodes that cross each other with a lower insulating layer positioned therebetween and take the form of a bar, and an upper insulating layer to cover the Y electrodes. The X and Y electrodes are connected to pad parts, such as voltage applying pads or voltage detection pads, by routing lines.

In some embodiments, the touch array 260 may include bridge electrodes formed on the upper flexible substrate 220 b, an insulating layer to cover the bridge electrodes, X electrodes formed on the insulating layer and electrically connected via the bridge electrodes, and Y electrodes formed at the same layer level as the X electrodes.

Next, as illustrated in FIG. 5C, an adhesive layer 270 is formed on the touch array 260, and the adhesive layer 270 is attached to the passivation layer 250. Then, the lower and upper rigid substrates 200 a and 200 b are adhered by curing the adhesive layer 270 so that the touch array 260 and the OLED array 240 face each other.

Subsequently, a high voltage, i.e., 3 kV to 5 kV, is applied to the upper exfoliation layer 210 b using a voltage applying device. In this regard, the voltage is applied for a period on the order of a microsecond, and thus the high voltage applied to the upper exfoliation layer 210 b is a pulse type voltage. Due to this, as illustrated in FIG. 5D, a gap is formed between the upper exfoliation layer 210 b formed of a metal or a transparent conductive oxide and the upper flexible substrate 220 b formed of a plastic film. Thus, as illustrated in FIG. 6A, the upper exfoliation layer 210 b is separated from a rear surface of the upper flexible substrate 220 b. In this regard, as illustrated in FIGS. 6B and 6C, routing lines of the touch array 260 are not disconnected.

Although not shown, the lower rigid substrate 200 a is cut on a unit panel basis, a PCB for driving the OLED array 240 is integrally formed with an FPCB for driving the touch array 260, and the FPCB is connected to the touch array 260 using an ACP.

Subsequently, a pulse type high voltage ranging from 3 kV to 5 kV is also applied to the lower exfoliation layer 210 a. As illustrated in FIG. 5E, when the voltage is applied to the lower exfoliation layer 210 a, a gap is formed between the lower exfoliation layer 210 a formed of a metal or a transparent conductive oxide and the lower flexible substrate 220 a formed of a plastic film. Accordingly, the lower exfoliation layer 210 a is separated from the lower flexible substrate 220 a.

Next, as illustrated in FIG. 5F, a top cover 280 is attached to a rear surface of the upper flexible substrate 220 b from which the upper exfoliation layer 210 a has been separated. The top cover 280 is formed of a material such as PMMA, PU, acryl, COP, PET, PEN, polyimide, or the like. Although not shown, a bottom cover may be formed on a rear surface of the lower flexible substrate 220 a.

According to the manufacturing method of the OLED display device having a built-in touch panel, a flexible substrate is formed on a rigid substrate with an exfoliation layer positioned therebetween, and an OLED array or a touch array is formed on the flexible substrate. In addition, the rigid substrate is separated from the flexible substrate using ultraviolet light. Therefore, an OLED display device including a built-in touch panel and having flexibility may be manufactured.

In particular, the OLED display device may be manufactured by integrating a PCB for driving the OLED array with an FPCB for driving the touch array, and thus manufacturing costs may be reduced.

As is apparent from the above description, the OLED display device having a built-in touch panel and the manufacturing method thereof have the following effects.

First, an OLED array and a touch array are formed on respective flexible substrates, and thus the OLED display device having a built-in touch panel has flexibility and decreased thickness.

Second, an FPCB for driving the touch array and a PCB for driving the OLED array are integrally installed, and thus manufacturing costs may be reduced.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. 

What is claimed is:
 1. An organic light emitting diode (OLED) display device comprising: an OLED array on a lower flexible substrate; a touch array on an upper flexible substrate; and an adhesive layer adhering the upper flexible substrate to the lower flexible substrate such that the touch array and the OLED array face each other.
 2. The OLED display device according to claim 1, wherein the touch array comprises X and Y electrodes crossing each other, a pad part, and a routing line connecting the pad part to the X and Y electrodes, wherein the pad part is connected to the OLED array via an anisotropic conductive paste.
 3. The OLED display device according to claim 2, wherein the anisotropic conductive paste has a first end connected to the pad part and a second end on the lower flexible substrate and connected to a flexible printed circuit board for driving the touch array.
 4. The OLED display device according to claim 3, wherein the flexible printed circuit board is integrally formed with a printed circuit board electrically connected to the OLED array to drive the OLED array. 